Photoresist stripping apparatus and internal air circulating system thereof

ABSTRACT

An apparatus for stripping photoresists from a substrate includes a reaction chamber, a plurality of air guiding means provided inside the reaction chamber, a pump for extracting air inside the reaction chamber, and a pipe for circulating and feeding the extracted air back into the reaction chamber. The upper and lower surfaces of the substrate are blown with the extracted air from the air guiding means.

FIELD OF THE INVENTION

The present invention relates to a photoresist stripping apparatus and, more particularly, to a photoresist stripping apparatus provided with an internal air circulating system.

GENERAL BACKGROUND

In fabrication of Thin-Film Transistors (TFTs) for a liquid crystal display, photoresists are used to define a configuration of the TFTs on a glass substrate. Then the photoresists are removed by using solvents such as Monoethanolamine (MEA), butoxydiglycol (BDG), N-Methyl-Pyrolidinone (NMP), etc. This removing process is known as a photoresist stripping process, and further includes steps of cleaning away the solvents, rinsing inter-media on the glass substrate with Isophorone (IPO) or Dimethyl Sulfoxide (DMSO), cleaning the glass substrate with water, and drying the glass substrate.

A typical photoresist stripping apparatus usually has several reaction chambers connected one after another, and these chambers perform the above-mentioned steps respectively. Since these chambers are similar in structure, illustration of the photoresist stripping apparatus can be simplified by referring to only one such reaction chamber, such as that shown in FIG. 3.

Referring to FIG. 3, one reaction chamber 11 of a photoresist stripping apparatus 10 has an inlet 12, an outlet 13, an exhaust port 21, a transmitting mechanism 14, a plurality of nozzles 15, and four air knives 16 a, 16 b, 16 c, and 16 d. The air knives 16 a˜16 d are provided inside the reaction chamber 11. In particular, the air knives 16 c and 16 d are positioned vertically at both sides of the inlet 12, while the air knives 16 a and 16 b are positioned vertically at both sides of the outlet 13. All the air knives 16 a˜16 d communicate with an air supply pipe 19, which in turn is connected with a plant system (not shown) and a pressure reducing device 20.

The transmitting mechanism 14 is inside the reaction chamber 11, between the inlet 12 and outlet 13. The transmitting mechanism 14 is for moving a glass substrate 100 into the reaction chamber 11 via the inlet 12 and out of the reaction chamber 11 via the outlet 13. The nozzles 15 are located above the transmitting mechanism 14. The nozzles 15 communicate with a cleaning fluid supply pipe 17, which in turn is connected with the plant system and a pump 18. The exhaust port 21 extends from an inner wall of the reaction chamber 11 and communicates with a pipe 22 and a pump 23 of the plant system, such that the pump 23 can extract and exhaust air inside the reaction chamber 11.

A cleaning fluid, such as solvent or water or a combination thereof, originates from the plant system. The cleaning fluid is compressed by the pump 18 and then delivered into the reaction chamber 11 via the cleaning fluid supply pipe 17. The cleaning fluid is then sprayed directly over the glass substrate 100 via the nozzles 15 to remove photoresist or particles on the glass substrate 100. Subsequently, clean dry air (CDA) originating from the plant system is pressure regulated by the pressure reducing device 20, and serves as an air source of the air knives 16 a˜16 d. The CDA passes through the air supply pipe 19 and blows upper and lower surfaces of the moving glass substrate 100 via the air knives 16 a˜16 d. Thereby, cleaning fluid remaining on the glass substrate 100 is removed, and the cleaning fluid is prevented from vaporizing into the surrounding environment.

Complete removal of liquid remaining on the glass substrate 100 usually requires a plant system to provide a lot of CDA and keep the output pressure of the air knives 16 a˜16 d at a constant value. Further, the pump 23 is required to have a larger displacement than the amount of CDA supplied from the air knives 16 a˜16 d, so that the reaction chamber 11 is always under a negative pressure condition. This imposes a heavy loading on the pump 23, which may in turn elevate the cost of operating the plant system.

What is needed is a system that provides a solution to the above-mentioned problems.

SUMMARY

An exemplary apparatus for stripping photoresists from a substrate is provided. The apparatus includes a chamber, a plurality of air guiding means provided inside the chamber, a pump for extracting air inside the chamber, and a pipe for circulating and feeding the extracted air back into the chamber. The extracted air blows upper and lower surfaces of the substrate via the air guiding means.

Basically, the chamber includes an inlet, an outlet, and a transmitting mechanism provided between the inlet and outlet for moving the substrate. Besides, the chamber basically includes a plurality of nozzles above the transmitting mechanism for spraying cleaning fluid, such as solvent or water or combination thereof, over the substrate to remove photoresist or particles on the substrate.

Furthermore, the chamber includes an opening communicating with the pump and the circulating pipe. Preferably, the opening is provided above the chamber and near the outlet.

The chamber still further includes an air feeding unit for supplying CDA and an air exhaust unit for exhausting air inside the chamber to keep a constant negative pressure condition inside the chamber.

Various embodiments of the present invention can be more fully understood by reading the subsequent detailed description and examples with reference made to the accompanying drawings. In the drawings, all the views are schematic, and at least certain of the drawings are simplified.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of one reaction chamber of a photoresist stripping apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of two reaction chambers of a photoresist stripping apparatus according to a second embodiment of the present invention.

FIG. 3 is a plan view of one reaction chamber of a conventional photoresist stripping apparatus.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A photoresist stripping apparatus according to various embodiments of the present invention includes a plurality of reaction chambers. Typically, there are several reaction chambers for performing steps of solvent cleaning, inter-media rinsing, water cleaning, and drying, respectively. These reaction chambers are similar in structure and connected one after another. In the following description and the drawings, for simplicity, only one reaction chamber of a first embodiment and two connected reaction chambers of a second embodiment are detailed and illustrated.

Referring to FIG. 1, one reaction chamber 31 of a photoresist stripping apparatus 30 of a first embodiment of the present invention is shown. The reaction chamber 31 includes an inlet 32, an outlet 33, a transmitting mechanism 34, a plurality of nozzles 35, an air suction port 44, an air exhaust port 45, an air feeding port 48, and an internal air circulating system 40. The internal air circulating system 40 includes an extraction pump 41, a circulating pipe 42, and a plurality of air guiding means such as four air knives 43 a, 43 b, 43 c, and 43 d. All the air knives 43 a˜43 d communicate with the extraction pump 41 via the circulating pipe 42. The air knives 43 a˜43 d are disposed inside the reaction chamber 31. The air knives 43 c and 43 d are set vertically at both sides of the inlet 32, while the air knives 43 a and 43 b are set vertically at both sides of the outlet 33. The internal air circulating system 40 is independent of an air feeding pipe 49 (see below), which air feeding pipe 49 is connected with a plant system.

The inlet 32 and the outlet 33 are an entrance and an exit for a substrate 200, respectively. Typically, the substrate 200 is a glass substrate. Each of the inlet 32 and outlet 33 can be closed by a movable gate to seal the reaction chamber 31 when necessary. The transmitting mechanism 34 is inside the reaction chamber 31 between the inlet 32 and outlet 33, so that the substrate 200 can be moved into the reaction chamber 31 via the inlet 32 and out of the reaction chamber 31 via the outlet 33. The nozzles 35 are above the transmitting mechanism 34, and communicate with a pipe 36, a pressure pump 38, and a cleaning fluid storing tank 37.

The air suction port 44 and the air exhaust port 45 are located in a top inner wall of the reaction chamber 31, while the air feeding port 48 is located in a bottom inner wall of the reaction chamber 31. The air suction port 44 is an opening communicating with the extraction pump 41 and the circulating pipe 42. The air exhaust port 45 communicates with a pipe 46 and an exhaust unit 47 of the plant system. The exhaust unit 47 includes an extraction pump for extracting and exhausting air inside the reaction chamber 31, such that the reaction chamber 31 is always under a constant negative pressure condition. The air feeding port 48 communicates with the air feeding pipe 49 and an air feeding unit 50. The air feeding unit 50 includes a pressure reducing device or an airflow controlling device for regulating pressure of CDA supplied from the plant system.

A cleaning fluid, such as solvent or water or a combination thereof, originates from the tank 37. The cleaning fluid can be compressed by the pressure pump 38 and then delivered to the reaction chamber 31. The cleaning fluid sprays directly over the substrate 200 through the nozzles 35 to remove photoresist or particles on the substrate 200. Subsequently, the air inside the reaction chamber 31 is extracted and properly pressurized by the extraction pump 41 and fed back to the reaction chamber 31 through the circulating pipe 42 and the air knives 43 a˜43 d. The circulated air therefore passes through the air knives 43 a˜43 d and blows upper and lower surfaces of the moving substrate 200 to remove the cleaning fluid on the substrate 200 and prevent the cleaning fluid from vaporizing into the surrounding environment. Meanwhile, CDA supplied from the plant system is regulated in pressure by the air feeding unit 50 and delivered to the reaction chamber 31 via the air feeding pipe 49 and the air feeding port 48. This process is called air refreshing.

It is to be noted that, in this embodiment, the air suction port 44 is provided above the reaction chamber 31 and near the outlet 33 such that the local region around the outlet 33 is under a stronger negative pressure condition. The purpose is to shorten the path for circulating air near the outlet 33 and avoid any leakage of air containing vaporized cleaning fluid from the outlet 33.

Referring to FIG. 2, two reaction chambers 31 a and 31 b of a photoresist stripping apparatus 60 according to a second embodiment of the present invention are shown. Each of the reaction chambers 31 a and 31 b is similar in structure to the reaction chamber 31 of the first embodiment. In particular, each reaction chamber 31 a, 31 b includes an internal air circulating system 40 a/40 b independent of a plant system. In other words, the reaction chamber 31 a/31 b includes an inlet 32 a/32 b, an outlet 33 a/33 b, a transmitting mechanism 34, a plurality of nozzles 35 a/35 b, an air suction port 44 a/44 b, an air exhaust port 45 a/45 b, an air feeding port 48 a/48 b, and an internal air circulating system 40 a/40 b. The internal air circulating system 40 a/40 b includes an extraction pump 41 a/41 b, a circulating pipe 42 a/42 b and air guiding means such as four air knives 431 a/432 a, 431 b/432 b, 431 c/432 c, and 431 d/432 d. In the following description, for simplicity, detailing of the structure of the reaction chambers 31 a and 31 b is omitted.

The reaction chambers 31 a and 31 b are connected in series so that the outlet 33 a of the reaction chamber 31 a and the inlet 32 b of the reaction chamber 31 b communicate with each other. The transmitting mechanism 34 is provided at a constant level inside the reaction chambers 31 a and 31 b and between the inlet 32 a and the outlet 33 b, for moving a substrate 300 into and out of the reaction chambers 31 a and 31 b via the inlets 32 a and 32 b and the outlets 33 a and 33 b. Typically, the substrate 300 is a glass substrate. The nozzles 35 a and 35 b above the transmitting mechanism 34 communicate with pipes 36 a and 36 b, pressure pumps 38 a and 38 b, and cleaning fluid storing tanks 37 a and 37 b, respectively.

The photoresist stripping apparatus 60 further includes an air feeding unit 61 and an air exhaust unit 62. The air feeding unit 61 includes pressure reducing devices or airflow controlling devices 50 a and 50 b for regulating pressure of CDA supplied from the plant system. The air exhaust unit 62 can include a single extraction pump (not shown) for both reaction chambers 31 a and 31 b. Alternatively, as shown in FIG. 2, the air exhaust unit 62 can include respective extraction pumps 47 a and 47 b for each reaction chamber 31 a and 31 b to extract and exhaust air inside the reaction chambers 31 a and 31 b such that the reaction chambers 31 a and 31 b are always under a constant negative pressure condition.

A cleaning fluid, such as solvent or water or a combination thereof, originates from the tanks 37 a and 37 b. The cleaning fluid can be compressed by the pressure pumps 38 a and 38 b, and then delivered to the reaction chambers 31 a and 31 b. The cleaning fluids spray directly over the substrate 300 through the nozzles 35 a and 35 b, to remove photoresist or particles on the substrate 300. Subsequently, the internal air circulating systems 40 a and 40 b provide respective circulating airflows in the reaction chambers 31 a and 31 b, to prevent the cleaning fluid from remaining on the substrate 300 and being carried to the next reaction chamber. Meanwhile, each of the reaction chambers 31 a and 31 b is supplied with CDA from the plant system via the air feeding unit 61 to accomplish air refreshing. Preferably, before entering the reaction chambers 31 a and 31 b, the CDA is pressure regulated by the pressure reducing devices or airflow controlling devices 50 a and 50 b of the air feeding unit 61.

In each of the above-described embodiments, the photoresist stripping apparatus employs an internal air circulating system for each reaction chamber. The internal air circulating system independently extracts the air inside each reaction chamber, and the extracted air is fed back and serves as an air source for the air knives. Further, the negative pressure of each reaction chamber is achieved directly by extracting the air inside the reaction chambers via an air exhaust unit. Thus, the amount of CDA supplied from the plant system can be substantially economized, and the loading on the air exhaust unit 62 can be mitigated. Accordingly, the operation cost of the plant system can be lowered.

It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set out in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms during which the appended claims are expressed. 

1. An apparatus for stripping photoresist from a substrate, the apparatus comprising: a chamber including an inlet, an outlet, and an opening; a transmitting mechanism provided inside the chamber for moving the substrate into the chamber via the inlet and moving the substrate out of the chamber via the outlet; a plurality of air guiding means provided inside the chamber at opposite sides of the inlet and opposite sides of the outlet; and a pump communicating with the opening and the air guiding means for extracting air inside the chamber and feeding back the extracted air into the chamber via the air guiding means such that the substrate is blown with the extracted air from the air guiding means.
 2. The apparatus as set forth in claim 1, further comprising a plurality of nozzles above the transmitting mechanism, the nozzles are configured for spraying cleaning liquid over a surface of the substrate.
 3. The apparatus as set forth in claim 2, wherein the cleaning fluid is selected from the group consisting of solvent, water, and any combination thereof.
 4. The apparatus as set forth in claim 1, wherein the air guiding means are air knives.
 5. The apparatus as set forth in claim 1, wherein the opening is above the chamber and near the outlet.
 6. The apparatus as set forth in claim 1, further comprising a first unit communicating with the chamber for exhausting air inside the chamber.
 7. The apparatus as set forth in claim 1, further comprising a second unit communicating with the chamber for feeding clean dry air into the chamber.
 8. An internal air recycling system in a photoresist stripping apparatus, the air recycling system comprising: a pump communicating with an opening of a chamber of the photoresist stripping apparatus for extracting air inside the chamber; a pipe communicating with the pump for circulating the extracted air; and a plurality of air knives communicating with the pump and the pipe; wherein the extracted air is fed back into the chamber via the air knives.
 9. An apparatus for stripping photoresist from a substrate, comprising: a plurality of chambers each comprising an inlet, an outlet and an opening, the chambers being connected one after another such that the outlet of one chamber communicates with the inlet of a next adjacent chamber; a transmitting mechanism provided inside the chambers for moving the substrate through the chambers; a plurality groups of air guiding means, each group being provided inside a respective chamber, the air guiding means of each group being positioned at opposite sides of the inlet and opposite sides of the outlet of the chamber; and a plurality of pumps each communicating with the opening and air guiding means of a respective chamber and configured for extracting air inside the chamber and feeding back the extracted air into the chamber via the air guiding means such that the substrate is blown by the extracted air from the air guiding means.
 10. The apparatus as set forth in claim 9, wherein each of the chambers further comprising a plurality of nozzles provided above the transmitting mechanism, the nozzles are configured for spraying cleaning fluid over a surface of the substrate.
 11. The apparatus as set forth in claim 10, wherein the cleaning fluid is selected from the group consisting of solvent, water, and any mixture thereof.
 12. The apparatus as set forth in claim 9, wherein the air guiding means are air knives.
 13. The apparatus as set forth in claim 9, wherein the opening of at least one of the chambers is provided above the chamber and near the outlet.
 14. The apparatus as set forth in claim 9, further comprising an air feeding unit communicating with each of the chambers for feeding clean dry air into each of the chambers.
 15. The apparatus as set forth in claim 9, further comprising an air exhaust unit communicating with each of the chambers for exhausting air inside the chambers. 